For an explanation of the various pieces of machinery, see Mill machinery.

South Marsh Mill is a five-storey tower mill. She had four Patent sails carried on a cast iron windshaft. The cap was a beehive shape, winded by a fantail. The mill drove three pairs of millstones. The cap now carried is an octagonal shape, housing the broken windshaft. The fantail is missing.[2] Various extensions have been made to the tower.[1]